\documentclass[10pt]{article} % required
\pagestyle{empty} % required
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{color}
\usepackage[T1]{fontenc}

\begin{document}\definecolor{fgC}{rgb}{0,0,0}\color{fgC}\[\begin{matrix}
T = \frac{p}{\rho R} \\

E = \rho e + \frac{1}{2} \rho u^2 \\

H = \rho h + \frac{1}{2} \rho u^2 \\

a = \sqrt{\frac{\gamma p}{\rho}}
\end{matrix}\]\end{document}